Conventionally, a valve structure, which is located at a bottom portion of a sub tank arranged in a fuel tank, and allows an inflow of fuel into the sub tank while preventing an outflow of the fuel from the sub tank, is well known.
For example, in a valve structure disclosed in Patent Document 1 (U.S. Pat. No. 8,511,340), an umbrella valve is located on a pumping passage through which fuel pumped into a sub tank from a fuel tank by a jet pump flows. When the fuel is injected into the pumping passage by the jet pump, a negative pressure is generated and thus the umbrella valve is opened so that pumping of the fuel into the sub tank through the pumping passage is realized. On the other hand, when the fuel injection by the jet pump is stopped, the generation of the negative pressure is also stopped and thus the umbrella valve is closed so that fuel storage in the sub tank is realized.
Meanwhile, fuel for injection needs to be stored in the sub tank in order for the fuel to be pumped by the jet pump, for example, as disclosed in Patent Document 1. Accordingly, the present inventors have studied a technique in which a natural inlet is provided at a bottom portion of the sub tank and the umbrella valve as the valve structure is also located at the natural inlet at the bottom portion of the sub tank, in addition to the pumping passage.
However, since each umbrella valve is assembled at a plurality of positions at the bottom portion of the sub tank in the technique, the assembly work may be complicated and it may be difficult to check whether the assembly state is correct. That is, there is concern that the technique may cause deterioration in assembly workability due to an increase of the number of parts.